Preparation And Properties Of Antibacterial And Thermo-sensitive Hydrogel Dressings

The rapid pace of modern society is accompanied by multiple injuries,and the emergence of various drug-resistant bacteria makes the research and development of new medical dressings as a means of topical wound treatment is becoming a hotspot.In this study,modified gelatin,N-isopropyl acrylamide and mupirocin were used as main experimental materials to prepare mupirocin thermo-sensitive hydrogel dressings.1)Firstly,gelatin was modified to produce acylated gelatin,and then five different mass ratios of thermo-sensitive hydrogel dressings were prepared.SEM and FT-IR were used to study the structure and surface morphology of the prepared hydrogel dressings.It was found that when the mass ratio of acylated gelatin and N-isopropyl acrylamide was 1:1,the pore structure of hydrogel dressing was the most uniform and dense.The swelling experiment was conducted at 25℃ and 37℃ respectively confirmed that the swelling trend of hydrogel dressings with five different mass ratio were different.At 25℃,the swelling rate was the highest when the mass ratio of acylated gelatin and N-isopropyl acrylamide was 1:1.The phase transition and temperature sensitivity of hydrogel dressings were verified by vials inversion and DSC.When the mass ratio of acylated gelatin and N-isopropyl acrylamide was 1:1,the phase transition temperature was32.08℃.The mechanical compression properties of hydrogel dressings were determined by universal testing machine.It was found that the compression property was enhanced with the increase of the ratio of acylated gelatin.2)Secondly,two thermo-sensitive hydrogels of mupirocin were prepared using dry soaking method(1mg/mL and 0.5 mg/mL mupirocin solution were used for soaking).The drug loading rate and drug release rate were calculated by ultraviolet spectrophotometry.The drug loading rate of the hydrogel dressing prepared using 1 mg/mL mupirocin solution was higher than that using 0.5 mg/mL mupirocin solution.The release rate was reversed.Among the five thermo-sensitive hydrogel dressings of mupirocin with different mass ratios,it has he highest loading rate and release rate when the mass ratio of the acylated gelatin and N-isopropyl acrylamide was 1:1,and the overall drug loading and release trend was similar to the swelling rate.3)Thirdly,staphylococcus aureus and escherichia coli were used as representatives to determine the bacteriostatic properties of thermo-sensitive hydrogel dressings of mupirocin,and it was found that bacteriostatic effects on staphylococcus aureus and escherichia coli were showed,and the bacteriostatic rate on escherichia coli was slightly higher than that on staphylococcus aureus.The bacteriostatic rate of hydrogel dressings prepared using 1 mg/mL mupirocin solution was slightly higher than that using 0.5 mg/mL mupirocin solution.The bacteriostatic rate of five dressings with different mass ratio increased when the mupirocin release rate increased.This research modified the gelatin,and introduced the thermo-sensitive material,which made preparation of the hydrogel dressing has better properties such as water absorption,mechanical strength and drug controlled release.It can give play to its advantages as a hydrogel dressing and allow the mupirocin to fully play the bactericidal effect in a short time,reducing drug resistance.Therefore,the hydrogel dressing preparation in this study will has a potential application prospect in the field of medical wound dressing.